Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

The study is billed as the first to show major depression can be chronic even in very young children, contrary to the stereotype of the happy-go-lucky preschooler.

Until fairly recently, "people really haven't paid much attention to depressive disorders in children under the age of 6," said lead author Dr. Joan Luby, a psychiatrist at Washington University in St. Louis. "They didn't think it could happen ... because children under 6 were too emotionally immature to experience it."

Previous research suggested that depression affects about 2 percent of U.S. preschoolers, or roughly 160,000 youngsters, at one time or another. But it was unclear whether depression in preschoolers could be chronic, as it can be in older children and adults.

Luby's research team followed more than 200 preschoolers, ages 3 to 6, for up to two years, including 75 diagnosed with major depression. The children had up to four mental health exams during the study.

Among initially depressed children, 64 percent were still depressed or had a recurrent episode of depression six months later, and 40 percent still had problems after two years. Overall, nearly 20 percent had persistent or recurrent depression at all four exams.

Depression was most common in children whose mothers were also depressed or had other mood disorders, and among those who had experienced a traumatic event, such as the death of a parent or physical or sexual abuse.

Controversial treatment
The new study, funded by the National Institute of Mental Health and released Monday in the August issue of Archives of General Psychiatry, did not examine depression treatment, which is highly controversial among children so young. Some advocates say parents and doctors are too quick to give children powerful psychiatric drugs.

Though sure to raise eyebrows among lay people, the notion that children so young can get depressed is increasingly accepted in psychiatry.

University of Chicago psychiatrist Dr. Sharon Hirsch said the public thinks of preschoolers as carefree. "They get to play. Why would they be depressed?" she said.

But depression involves chemical changes in the brain that can affect even youngsters with an otherwise happy life, said Hirsch, who was not involved in the study.

"When you have that problem, you just don't have that ability to feel good," she said.

And, in fact, Luby said she has separate, unpublished research showing that chemical changes seen in older children also occur in depressed preschoolers.

Dr. Helen Egger, a Duke University psychiatrist who also has studied childhood depression, said it is common among people in her field to first see depressed kids in their teens. Their parents will say symptoms began very early in childhood, but they were told, "Your child will grow out of them," Egger said.

Sad even when playingTypical preschoolers can be moody or have temper tantrums, but they quickly bounce back and appear happy when playing or doing everyday activities. Depressed children appear sad even when playing, and their games may have themes of death or other somber topics. Persistent lack of appetite, sleep problems, and frequent temper tantrums that involve biting, kicking or hitting also are signs of possible depression, Egger said.

Luby said another sign is being preoccupied with guilt over common mishaps. For example, a depressed 3-year-old who accidentally breaks a glass might keep saying, "Mommy, I'm sorry I did that," and appear unable to shake off that sense of guilt for days, she said.

University of Massachusetts psychologist Lisa Cosgrove said she is skeptical about the accuracy of labeling preschoolers as depressed, because diagnostic tools for evaluating mental health in children so young aren't as well tested as those used for adults.

And Cosgrove said that while early treatment is important for troubled children, "we just have to make sure that those interventions aren't compromised" by industry pressure to use drugs.

Previous research has suggested that rising numbers of preschoolers are taking psychiatric drugs, including Prozac, which is used to treat depression.

Egger said that there is little research on the effects of psychiatric medicine in very young children, and that psychotherapy should always be tried first.

Dr. David Fassler, a University of Vermont psychiatry professor, stressed that depression in very young children is still pretty rare. However, without treatment, "it can have a devastating and often lasting effect on a child's social and emotional development," he said.

"Hopefully, studies such as this will help parents, teachers, and pediatricians recognize the signs and symptoms of preschool depression so they make sure young children get the help they need and deserve," Fassler said.